05 February 2008, Volume 34 Issue 3
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Computer Engineering. 2008, 34(3): 1-2,5. https://doi.org/10.3969/j.issn.1000-3428.2008.03.001A forecasting method for nonlinear time series based on Relevance Vector Machine(RVM) is proposed for the purpose of dealing with the complexity and uncertainty during engineering modeling. Based on the traditional kernel functions, RVM using a sparse kernel representation can directly provide probabilistic forecasting results under Bayesian frame. The method is simple and easy to be realized without pre-calculation of error/margin parameters. Simulation instance shows that the method reflects inherent characteristics of nonlinear time series, exhibits high model efficiency and provides satisfying forecasting precision.
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Computer Engineering. 2008, 34(3): 3-5. https://doi.org/10.3969/j.issn.1000-3428.2008.03.002Attribute reduction is one of key problems in the theoretical research of Rough sets, and many algorithms have been proposed to study it. These methods may be divided into two classes (addition strategy and deletion strategy). This paper proposes a new algorithm based on attribute frequency in the discernibility matrix. In order to find optimum Pawlak reduction of decision tables, it adds the converse eliminate action until cannot delete. Tests indicate that the method performs faster than others.
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Computer Engineering. 2008, 34(3): 6-8. https://doi.org/10.3969/j.issn.1000-3428.2008.03.003This paper uses similarity rules, complementary rule and molecular recognition theory to set up a digital coding model of amino acid for investigation into sequence features and their function identification. Cellular automata is used to generate image representation for protein sequences. A protein sequence can be represented by a unique image, and the image considers the interactional actions between amino acids. Many important features hidden in protein sequence can be revealed through its cellular automata image. The protein subcellular location prediction rate reaches 86.4% based on the visualization model.
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Computer Engineering. 2008, 34(3): 9-11. https://doi.org/10.3969/j.issn.1000-3428.2008.03.004Among the decision tree generation algorithms, which are based on rough set model, existing algorithms usually partition examples too detailedly to avoid the negative impact caused by a few special examples on decision tree because of the classification accuracy. This leads to that the generated decision tree seems too large to be understood. It also weakens its classification ability and predictable ability on data to be classified or predicted. In order to solve these problems, a new algorithm for generating decision tree based on rough set model is proposed. It introduces hold-down factor, which is an additional terminal condition for expanding nodes, besides traditional one. For generating node, if the hold-down factor of some sample is bigger than the given threshold, the node will not be expanded any more. Thus, the problem of too detailed partition is avoided. The size of decision tree generated by the proposed algorithm will not be too large to understand for the user.
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Computer Engineering. 2008, 34(3): 12-14,1. https://doi.org/10.3969/j.issn.1000-3428.2008.03.005Localization is one of the supporting technologies in wireless sensor networks. In this paper, a novel sampling localization and refinement distributed algorithm is described and evaluated. The algorithm includes two stages. In first stage, sampling is carried out based on received anchor information and the initial position estimate of sensor node comes into being. In second stage, the initial node position is refined. Simulation results show this algorithm is convergent under 1~2 refinement times and achieves high localization accuracy in low sample size threshold as 20. It also gets 95% localization coverage when anchor ratio is about 12%. Comparing with dv-hop and dv-distance methods, it improves localization accuracy by 20% and 5%.
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Computer Engineering. 2008, 34(3): 15-17. https://doi.org/10.3969/j.issn.1000-3428.2008.03.006
This paper proposes a video text tracking and text stroke extraction method under complex background. A point matching method based on Harris corner features is introduced to track text objects. The performance is evaluated by the comparison with SSD-based tracking method. A multi-frame-based foreground/background recognition algorithm is proposed to extract text strokes for optical character recognition. The efficiency and robustness of the point matching method for video text tracking and the text stroke extraction algorithm are proved by objective and thorough experiments on TV serials and movies.
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Computer Engineering. 2008, 34(3): 18-20. https://doi.org/10.3969/j.issn.1000-3428.2008.03.007Focussing on the transitive mode reputation computing algorithm in reputation systems, the information losing problem caused by normalization, computing Global Reputation Value (GRV) using relative value, and the difference of rating function criteria, and the problem caused by indefinite inference of peer’s certain factor are analyzed. This algorithm is improved based on certain factor. Simulation results show that the Euclidean distance between the computed GRV sequence and ideal value is much smaller by using improved algorithm, which enhances the ability to discover malicious peers.
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Computer Engineering. 2008, 34(3): 21-23,6. https://doi.org/10.3969/j.issn.1000-3428.2008.03.008Searching the attacking locomotion trajectory is a valid method for the barrier-coverage control in wireless sensor networks. Without any information of topology, an algorithm called as SS(Security & Speed)algorithm, is presented to build attacking locomotion trajectory. This trajectory can image the different of above two demands. Compared with the traditional worst-coverage algorithm, the proposed SS algorithm can match the results of the optimal more closely and has smaller complexity than the optimal approach.
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Computer Engineering. 2008, 34(3): 24-26. https://doi.org/10.3969/j.issn.1000-3428.2008.03.009This paper proposes a three DOF vision servoing method based on texture analyzing. The theory based on geography characteristics calculation will not be effective in the environment full of texture but short of geography characteristics. By analyzing the relationship between the camera motions and the coarseness changing of the texture image, a vision servoing method based on texture coarseness analyzing is given. The result of half-physical robot station keeping experiment shows that the changing of texture characteristics can provide enough motion information for the servoing task of the robot.
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Computer Engineering. 2008, 34(3): 27-28,5. https://doi.org/10.3969/j.issn.1000-3428.2008.03.010Support Vector Machine (SVM) is to correctly classify samples into two parallel planes in input or feature space by optimal planes (lines). And the margin between the two classes is made to be the largest. The standard SVM requires to solve quadratic program that needs considerable computational time. Based on a concrete decision support system of medical images, a novel algorithm is introduced to solve the problem. Experimental results on UCI and a developed decision support system demonstrate that the presented algorithm is simple, feasible, and faster with better precision.
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Computer Engineering. 2008, 34(3): 29-31. https://doi.org/10.3969/j.issn.1000-3428.2008.03.011Finding association rules is a major aspect of data mining research. An efficient algorithm FIAFAR is proposed to deal with incremental mining of association rules. Algorithm is based on the CAN-tree structure, overcomes the shortcomings of FP-tree which it is not suitable for incremental mining and minimum support varying. The children to parent pointer is used in algorithm instead of parent to children pointer. It helps algorithm FIAFAR build conditional pattern tree effectively and improves the efficiency of algorithm in consequence. Experimental results show that the new algorithm is effective for large databases.
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Computer Engineering. 2008, 34(3): 32-34,3. https://doi.org/10.3969/j.issn.1000-3428.2008.03.012This paper presents a method based on Element Path Models(EPM) for extracting XML Schema to enhance the efficiency of XStruct supposed by Hegewald, etc. XML Schema is generated by element sequence expression which is merged from element path models while parsing XML documents with SAX. Experiment shows that the method based on EPM uses less time and space than XStruct.
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Computer Engineering. 2008, 34(3): 35-37. https://doi.org/10.3969/j.issn.1000-3428.2008.03.013Optimal design is significant when the DSP software is designed by C programming language. A number of different algorithms for optimized offset assignment in DSP code generation are developed recently, which aim at constructing a layout of local variables in memory, so that the addresses of variables can be computed efficiently. This paper presents a quasi-PSO optimization algorithm integrating PSO algorithm and genetic algorithm. The address assignment of each variable in the variable access sequence is optimized to maximize the use of auto-increment operations on address registers. This method minimizes the needed code for address computation, so as to maximize code speed and efficiency of DSP.
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Computer Engineering. 2008, 34(3): 38-39,4. https://doi.org/10.3969/j.issn.1000-3428.2008.03.014Security analysis of P. Paillier(etc)’s public-key encryption scheme(P-P) is proposed. Equivalent relations of one-wayness of P-P encryption scheme with other problems are verified. So without lowering the security, this paper improves the efficiency and reduces the data to be transferred by using proper parameters. The improved encryption scheme is specified, with the process of encryption/decryption being more efficient than that of P-P encryption scheme.
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Computer Engineering. 2008, 34(3): 40-42. https://doi.org/10.3969/j.issn.1000-3428.2008.03.015This paper proposes a client dynamic self-adaptive replica selection algorithm in high energy physics grid environment. The algorithm predicts the replica selection based on the transfer histories, and it can also be configured easily for different applications. Mathematic derivation and experimental results are given to show that the algorithm can meet the requirements of high energy physics grid.
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Computer Engineering. 2008, 34(3): 43-45,6. https://doi.org/10.3969/j.issn.1000-3428.2008.03.016This paper presents a task scheduling and matching technique based on generic Evolutionary Algorithm(EA)——SASGA for heterogeneous systems, and makes a performance comparison with traditional GAs on scheduling problems. Simulation experimental results show SASGA can generate higher solutions quality and may enhance the searching ability. Thus it can be concluded that the proposed method will be a promising algorithm for task scheduling in heterogeneous systems.
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Computer Engineering. 2008, 34(3): 46-48. https://doi.org/10.3969/j.issn.1000-3428.2008.03.017With the improvement of the size and integration degree of the reconfigurable hardware such as FPGA, more hardware tasks can run on FPGA concurrently. The tasks can be added to or deleted from FPGA dynamically without interference to other running tasks due to the partially dynamical reconfiguration. So the management of reconfigurable hardware resources is very important. This paper provides a Task-Top based Keep All Maximal Empty Rectangles (TT-KAMER) algorithm. Maximal Empty Rectangles(MERs) can efficiently represent all the empty resources on FPGA. Results show that TT-KAMER can compute all the MERs efficiently, and facilitate the utilization of the partially dynamical reconfigurable hardware.
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Computer Engineering. 2008, 34(3): 49-51,5. https://doi.org/10.3969/j.issn.1000-3428.2008.03.018The architecture of grid resource management system oriented to information services is put forward, which has been divided into global and local resource management system. And a new job scheduling algorithm is provided to meet the request of information and service grid. The algorithm can predict the RT(Running Time) of current job according to the same type jobs’ historical records of the RTs and schedule those jobs depending on both of the RT and end time. The experiment shows that the algorithm is more efficient than popular algorithm, such as Min-Min and Max-Min.
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Computer Engineering. 2008, 34(3): 52-55. https://doi.org/10.3969/j.issn.1000-3428.2008.03.019In order to mitigate the effect of NLOS propagation, a TDOA/AOA localization algorithm based on the RBF neural network is proposed. The RBF neural network is made use of to correct the error of NLOS propagation, then position is calculated by TDOA/AOA algorithm. The simulation results indicate that the effect of NLOS propagation is mitigated by this algorithm. Its location accuracy is significantly improved and the performance of this algorithm is better than that of TDOA/AOA algorithm, Taylor algorithm, Chan algorithm and LS algorithm in NLOS environment.
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Computer Engineering. 2008, 34(3): 56-58. https://doi.org/10.3969/j.issn.1000-3428.2008.03.020Traditional matching methods of DDM are analyzed and a new region matching method is proposed with spatial index method. Publication regions and subscription regions are organized and managed by constructing a R-tree and matching operation is implemented in the R-tree. The results of simulation experiments show that time cost of R-tree region matching algorithm for DDM is lower by choosing appropriate M parameter. Therefore, it is proved that the algorithm has good performance.
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Computer Engineering. 2008, 34(3): 59-61. https://doi.org/10.3969/j.issn.1000-3428.2008.03.021Considering characters of GML spatial data, using the predications of OpenGIS® filter encoding implementation specification as query key words, transforming and optimizing the query expression by middleware, this paper presents an accessible method to implement query for GML spatial data according to filter encoding proposed by OGC. The objective is to provide one way that can help to achieve the query given data from massive GML spatial data, which is the focus of GML research along with geographic data transferring through Internet and GML spatial data application increasingly.
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Computer Engineering. 2008, 34(3): 62-65. https://doi.org/10.3969/j.issn.1000-3428.2008.03.022This paper proposes an enterprise engineering meta-methodology based on knowledge and rule which can consult relevant enterprise architecture, methodology, modeling framework, modeling language, modeling tool knowledge and their applying rule in modeling knowledge warehouse in each of its decision process. Engineering instance proves the feasibility of this meta-methodology.
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Computer Engineering. 2008, 34(3): 66-68,7. https://doi.org/10.3969/j.issn.1000-3428.2008.03.023Design pattern, as a smart design scheme for certain problems in object-originated software design, is successfully applied in many software projects. Remote sensing image software design and development is a complicated project, in which the remote sensing IO class design, algorithm class design and view class design are the most important parts. This paper elaborates how to design the three classes for remote sensing image processing based on design pattern.
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Computer Engineering. 2008, 34(3): 69-71. https://doi.org/10.3969/j.issn.1000-3428.2008.03.024Aiming at limitations of the current software fault diagnosis of the software-intensive equipment, this paper presents a new method based on both coarse-grained diagnosis and fine-grained diagnosis for the software fault location, discovers fault location, finds the set of the suspicious module, uses slicing algorithm to check the set of fault module, positions the fault to the program code set, eliminates the codes with assistant tool and locates the fault codes. The method is proved to be effective for software fault location by practice of fault diagnosis system of software-intensive equipment.
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Computer Engineering. 2008, 34(3): 72-74. https://doi.org/10.3969/j.issn.1000-3428.2008.03.025Resource and environmental models are made of a two-level model abstraction hierarchy: model class and model instance. A strategy for model composition is proposed based on model class. With Visual C++.net 2003 and Windows 2000, model class and model instance are constructed by object-oriented method. Model composition is manipulated through flowchart. Results show that flowchart can well integrate model composition with Graph User Interface (GUI), and the friendliness of Resource and Environmental Model-based Management System(REMMS) is increased.
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Computer Engineering. 2008, 34(3): 75-77,8. https://doi.org/10.3969/j.issn.1000-3428.2008.03.026Focusing on the drawback of the traditional business intelligence tools that they are difficult to be integrated with the business process, this paper introduces the principle of designing the business intelligence platform based on business process, then the SBBIP(SOA-Based Business Intelligence Platform) is given. SBBIP seamlessly integrates the BI component with the enterprise business process, as well as the external system and the legacy system through an integrating mechanism that is based on SOA. This paper proposes the model of developping enterprise solution based on SBBIP as well as an application instance based on SBBIP.
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Computer Engineering. 2008, 34(3): 78-80. https://doi.org/10.3969/j.issn.1000-3428.2008.03.027In order to save costs of software rejuvenation and improve software availability and reliability, rejuvenation granularity is improved to the component-level and the nested software rejuvenation policy is executed. Based on coupling relation among components of the software systems, this paper puts forward a method to search the direct coupled processes, sets down the rule of building component restart tree of system, and establishes the nested software rejuvenation policy on component-level. It supports to execute software rejuvenation with fine rejuvenation granularity.
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Computer Engineering. 2008, 34(3): 81-82,9. https://doi.org/10.3969/j.issn.1000-3428.2008.03.028By analyzing the minimum merge dependency set characteristics of F in FD set, the elementary merge dependency set and minimum merge dependency set are presented. Notions of weak left side conflict, weak right side conflict under elementary merge dependency set of F and Pek(join-lossless, FD and Elementary Key Normal Form(EKNF)) are introduced. The scheme decomposition is discussed and the result concludes that when the elementary merge dependency set of F has weak left side conflicts or weak right side conflict, the decomposition meeting Pek has α-cyclic. Experimental results show that the decomposition algorithm is effective.
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Computer Engineering. 2008, 34(3): 83-84,8. https://doi.org/10.3969/j.issn.1000-3428.2008.03.029This paper proposes a new method to generate test cases automatically. The method is based on function test and hierarchical framework. It extracts function component based on operation flow from requirement specification, maps and recomposes test scripts, generates test case with input data. The construct of function components adopts hierarchy structure, i.e. one function components may contain one or more components. Test-case generation can share the script in the more extent.
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Computer Engineering. 2008, 34(3): 85-87. https://doi.org/10.3969/j.issn.1000-3428.2008.03.030Bittorrent is the P2P system which works on central index server. The peer must get an expansion named torrent index file from the central index server before downloading. The index server becomes the bottleneck of the system. A torrent file optimization strategy based on Merkle tree is proposed, which makes the torrent file size smaller than before and lightens the overhead of the index server, improves the scalability of BT.
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Computer Engineering. 2008, 34(3): 88-90. https://doi.org/10.3969/j.issn.1000-3428.2008.03.031This paper discusses feasibility of anomaly detection based on outlier mining, presents an anomaly detection method by using an outlier detection method based on similar coefficient sum. It transforms the character feature into numerical value by code mapping, and uses Principal Components Analysis(PCA) to reduce dimension. Implementation method is proposed, feasibility of the method is proved.
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Computer Engineering. 2008, 34(3): 91-93. https://doi.org/10.3969/j.issn.1000-3428.2008.03.032This paper proposes an algorithm named boundary pattern detection based on statistics information to detect boundary points of clusters effectively. BOURN sets neighborhood radius based on the k-dist statistics information of the objects, and searches boundary points based on the k-dist statistics information of neighbors in the neighborhood around it. Experimental results show that BOURN can find boundary points of clusters of arbitrary shapes, different sizes and different density, and can remove noise effectively.
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Computer Engineering. 2008, 34(3): 94-96,9. https://doi.org/10.3969/j.issn.1000-3428.2008.03.033In order to mine fast and efficiently frequent closed itemsets according to insertion, deletion and modification of the database, this paper proposes an incremental maintaining algorithm U_CHARM based on CHARM algorithm. The algorithm partitions data into different groups to achieve the update of frequent closed itemsets, in which changed data are used to mine frequent closed itemsets and valid information is obtained from previous results by utilizing the properties of IT pairs. Experimental results demonstrate that the algorithm is fast and efficient.
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Computer Engineering. 2008, 34(3): 97-99. https://doi.org/10.3969/j.issn.1000-3428.2008.03.034This paper studies the management model of multi-cluster, presumes two methods: user-decided and system-decided, and stabiles a MCJSS structure based on PBS. Implement the core of MCJSS to manage job submit, forward job and collect load information. It gives the schedule policy based on prediction of low load. Serve the job forwarding mechanism by using load information collection of two levels, judge the time to forwarding job and the destination. It is proved through experiment that the throughput of multi-cluster is higher than single model cluster model under submission of same number of jobs to same scale nodes.
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Computer Engineering. 2008, 34(3): 100-101,. https://doi.org/10.3969/j.issn.1000-3428.2008.03.035This paper proposes Island+ method improving Island method in three aspects: network modeling, traffic-jam exploration and optimization of Island’s radius, which is efficient to answer kNN search in constrained road network. By using transition matrix representation and radius optimization method, the search efficiency is better than the old method, including search time and I/O pages access.
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Computer Engineering. 2008, 34(3): 102-104. https://doi.org/10.3969/j.issn.1000-3428.2008.03.036The act of a processor writing data into a currently executing code segment with the intent of executing that data as code is called self-modifying code. As processor architectures become more complex and start to speculatively execute code ahead of the retirement point, the rules regarding which code should execute, pre- or post-modification, become blurred. Although SMC seldom happens in current normal applications, it is necessary to handle this situation for programs with SMC. This paper analyses several methods for SMC handling, and gives a facile method that can be easily implemented. This method has been implemented on Godson-X processor model.
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Computer Engineering. 2008, 34(3): 105-107. https://doi.org/10.3969/j.issn.1000-3428.2008.03.037Selectivity Estimation is the base of spatial database query optimizer. This paper uses MBR buffer area and line segment buffer area of spatial object, according to the characteristics of data set in spatial join and distributed law of characteristic data, putting forward a selectivity estimation method based on point buffer area, which is used in spatial join selectivity estimation of characteristic data. Experiment proves that the method does well in use of the spatial join selectivity estimation of characteristic data and decreases the relative error clearly when characteristic data are estimated.
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Computer Engineering. 2008, 34(3): 108-110. https://doi.org/10.3969/j.issn.1000-3428.2008.03.038Although optimistic concurrency control approach is better than locking protocols for Real-time Database System(RTDBS), it has the problems such as unnecessary restarts and heavy restart overhead. This paper identifies the unnecessary restart problem in OCC-TI and proposes two extensions to the basic dynamic adjustment of the serialization order conflict resolution method used in OCC-TI. A new protocol named OCC-CPTI based on timestamp interval is proposed. Experiments with prototype implementation of a real-time database system show that the method outperforms the original OCC-TI method.
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Computer Engineering. 2008, 34(3): 111-112,. https://doi.org/10.3969/j.issn.1000-3428.2008.03.039In the simple situation, curriculum arranging schedule can be transformed to an edge coloring model of bipartite graphs, but it only describes the relations of teachers, classes and time, except classrooms, so the model is too simple to solve the practical problem. This paper extends it based on edge coloring through adding the relation of the classroom. The new model can solve the integrated problem.
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Computer Engineering. 2008, 34(3): 113-115. https://doi.org/10.3969/j.issn.1000-3428.2008.03.040A parasite is defined as code that is injected into a host executable. There are many potential uses for parasite code: binary decryption, unpacking and copyright protection, to name a few. And the most common form of parasite is the virus. Development of feature rich Linux parasites is severely limited by the inability to reliably access functions external to the host file. This paper explores the dynamic linking mechanisms of the Executable and Linkable Format(ELF), and brings up a methodology that allows parasite code access to shared objects. The implementation of this methodology is presented.
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Computer Engineering. 2008, 34(3): 116-118. https://doi.org/10.3969/j.issn.1000-3428.2008.03.041This paper proposes a pattern-based CPPVM parallel programming method based on study of the existing parallel programming methods. The design and implementation of parallel programming patterns is stressed and described. The process of applying the method to solve parallel problems and develop parallel programs is also introduced through two case studies. The method has an important effect on improving the programmability, reliability and development efficiency of parallel programs.
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Computer Engineering. 2008, 34(3): 119-121. https://doi.org/10.3969/j.issn.1000-3428.2008.03.042When Unified Modeling Language(UML) is widely accepted by the industry, it also becomes one kind of standard modeling language which the academic community follows. Many researches on object-oriented software test focus on deriving software models from the UML diagrams. UML offers effective modeling ability, but lacks well-defined semantic base for its notation. Petri nets can provide a formal semantic framework for the UML notations plus the behavioral modeling/analysis strength. This paper presents a method that gets the Colored Petri Nets (CPN) models from the UML diagrams. The method utilizes the state machine diagrams and the sequence diagrams. The framework of the support tool, U2CPN, is also presented.
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Computer Engineering. 2008, 34(3): 122-123,. https://doi.org/10.3969/j.issn.1000-3428.2008.03.043At present, core routers contain a huge number of buffers to hold packets during congestion, which assures high rate of linking utilization, but leads to high complication for routers design. Stanford model suggests that the buffer size can decrease to 1% of Bandwidth Delay Product (BDP). This paper analyzes the buffer size and shows that the Stanford model can lead to high drop rate of packets. Low drop rate and high throughput can be obtained with smaller buffer size in an acceptable link utilization.
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Computer Engineering. 2008, 34(3): 124-126. https://doi.org/10.3969/j.issn.1000-3428.2008.03.044In the context-aware application server, large amount of context information must be collected and processed. Server cluster and load balance are critical technique to ensure the availability and reliability of context-aware server. This paper presents the predicting based load balance algorithm, which allocates task dynamically using SVM to predict the system load in next time phase and consider the current load of all nodes in the system at the same time. The task cannot be transferred to another machine when it is already allocated to one node, which can reduce the consumption of system resource. Comparison of load balancing algorithms shows that the prediction algorithms can improve the performance of server when the system load changes dramatically.
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Computer Engineering. 2008, 34(3): 127-129. https://doi.org/10.3969/j.issn.1000-3428.2008.03.045With the rapid development of the network technologies, conventional network management systems are hard to meet the increasing requirements. This paper studies the adoption of XML technology in network management, introduces an XML gateway to make the XML-based network management system deployable in legacy SNMP-based network environments, and implements a universal configuration manager which can provide unified, GUI-based configuration service.
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Computer Engineering. 2008, 34(3): 130-132,. https://doi.org/10.3969/j.issn.1000-3428.2008.03.046This paper describes the implementation principle and flow of power control mechanism in IEEE 802.16e protocol. A power control algorithm based on the position information is proposed. Simulation results demonstrate that, at the expense of sacrificing small throughput, the proposed algorithm reduces the interference from the users on the edge of a cell to other neighboring cells. Subsequently, the blocking probability of the entire system is reduced dramatically when the number of users in a cell is huge, at the level of about 5%. This effect is especially obvious by comparing the new algorithm with the formal algorithms, which does not distinguish the positions.
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Computer Engineering. 2008, 34(3): 133-135. https://doi.org/10.3969/j.issn.1000-3428.2008.03.047Computing model of nodes has an important effect on the network performance and the mobile agent computing model for the next generation network has attracted more and more attentions. The background of mobile agent applied in the wireless sensor network is first analyzed. Then a framework based on mobile agent is proposed from two levels, namely network and nodes. After introducing the basic elements, functional definitions and interfaces of the framework, an implementation mechanism based on directed diffusion for mobile agent is presented.
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Computer Engineering. 2008, 34(3): 136-138. https://doi.org/10.3969/j.issn.1000-3428.2008.03.048From the thinking in content management system, this paper abstracts different content types from various kinds of network information and designs architecture of the network information management platform based on the open source content management development environment. This architecture is programmed with Python as primary language to achieve logistic function, and integrates AJAX with page marked language, such as DTML and ZPT to realize exhibition layer. Experimental results show that the platform is economical, practical, stable and efficient. It is convenient to development.
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Computer Engineering. 2008, 34(3): 139-140,. https://doi.org/10.3969/j.issn.1000-3428.2008.03.049Aiming at the shortcomings of Random Early Detection (RED) algorithm, such as poor stability, this paper analyzes the changing rules of factors which determine the performance of RED, according to the theory of queue. It concludes that the queue-length of buffer queue is non- linear, and the dropping probability rises with the rise of average queue-length, but not a linear function. This article presents an improvement algorithm named URED, and several simulation results prove it has better stability.
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Computer Engineering. 2008, 34(3): 141-144. https://doi.org/10.3969/j.issn.1000-3428.2008.03.050Based on the optimality principle of divisible load theory and the fixed sequence of text distribution, an optimal text distribution strategy is presented and its corresponding closed-form expressions are given in the heterogeneous cluster computing systems that processors have different computing speeds and communication capabilities. A linear programming model for the optimal text distribution is constructed for the cluster system that processors have different computing speeds, communication capabilities and memory capacities. The optimal text distribution sequence for special cases is studied. Experimental results show that the required parallel processing time for approximate string matching by applying the optimal text distribution strategy decreases 10%~40% and 5%~20% respectively compared with dividing the text equally and dividing the text according to the computing speeds of processors.
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Computer Engineering. 2008, 34(3): 145-147,. https://doi.org/10.3969/j.issn.1000-3428.2008.03.051In order to solve the problem on channel stability and anonymous security existing in P2P based anonymous communication network, this paper presents a new P2P based anonymous communication system called TreeMix. Strategies including dynamic index peers, reputation and IP prefix based peer selection, multi-channel, dynamic relay group are introduced into unstructured P2P network to build the TreeMix System. This system is proved more resistant to peer failure without loss of extensibility and can solve the communication efficient problem better by simulation experiment and data analysis.
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Computer Engineering. 2008, 34(3): 148-150. https://doi.org/10.3969/j.issn.1000-3428.2008.03.052This paper proposes a novel scheme based on pingpang handoff (mobile node’s frequent handoff between PAR and NAR) for predictive fast handovers for mobile IPv6 to solve the problems of long latency, high lost packets and excessive signaling redundancy in exiting schemes. It defines a new Hop-by-Hop option header named TM, PCoA table and tunneling table. TM is put in the acknowledgement of the last packets between NAR and PAR, telling PAR that MN would be back to the region of PAR in the near future, and hoping that the previous bidirectional tunneling between PAR and NAR is available, so that MN could implement its fast and smooth handovers. Analysis shows that this scheme is viewed as an effective method to solve the above problems and can improve the quality of service for mobile users.
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Computer Engineering. 2008, 34(3): 151-153. https://doi.org/10.3969/j.issn.1000-3428.2008.03.053This paper studies ATL logical and its applications in formal analysis of E-commerce protocols, and extends Dr Kremer’s approach to analyze security of protocols besides fairness. Strict formal analysis is made for FNORP protocol proposed by Zhou Mingtian etc. and is variations with this new method. The results indicate that the ATL logic based on game is more suitable to describe and analyze complex E-commerce protocols than traditional CTL.
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Computer Engineering. 2008, 34(3): 154-156. https://doi.org/10.3969/j.issn.1000-3428.2008.03.054Program behavior control system includes program behavior model, detection and response. One-class Support Vector Machine (SVM) has good classification accuracy and generalization in the case of limited samples. In former research of anomaly detection using one-class support vector machine, the attribute weights are not considered. This paper presents a method to introduce weights that reflect attribute importance using Rough Set Theory (RST). The kernel function of one-class support vector machine is adjusted by calculating attribute weights though finding all reducts in the decision system. Experimental results show that the one-class support vector machine with adjusted kernel function using rough set theory has more effective detection capability.
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Computer Engineering. 2008, 34(3): 157-159,. https://doi.org/10.3969/j.issn.1000-3428.2008.03.055This paper constructs a kind of provably secure group signature scheme with authorization based on the BMW’s scheme. Compared with BMW’s scheme, adding authorization generation algorithm to key generation algorithm in group signature scheme, although the speed of instance production of group signature scheme slows down, it strengthens group signature scheme with authorization characteristic, which makes group signature application in electronic business and electronic politics further step.
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Computer Engineering. 2008, 34(3): 160-162. https://doi.org/10.3969/j.issn.1000-3428.2008.03.056The prevailing of RFID arouses the security concern. Re-encryption is an approach with many advantages among approaches for RFID security. This paper describes the advantage of re-encryption and introduces the development of the application of re-encryption in RFID security. It promotes an application model for re-encryption in RFID security and security requirement, and points out that re-encryption has its short points. As to the tracking problem between re-encryption, it promotes the solution, and discusses the solution for the swapping attack in re-encryption system.
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Computer Engineering. 2008, 34(3): 163-164,. https://doi.org/10.3969/j.issn.1000-3428.2008.03.057Based on the thoroughly researches and analysis on the WLAN Authentication and Privacy Infrastructure (WAPI) access authentication process, i.e. the WAI protocol, this paper analyzes and verifies its authentication access process with CK model. Result of analysis indicates that the authentication access process of WAI can meet the security requirements of WLAN, such as data privacy protection, integrity protection, mutual identity authentication, mutual key control, private-key confirmation, etc. Therefore, WAPI can be applied to replace the original security mechanism WEP used in WLAN and to enhance its security.
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Computer Engineering. 2008, 34(3): 165-167. https://doi.org/10.3969/j.issn.1000-3428.2008.03.058Traditional Intrusion Detection Systems(IDSs) requires prior knowledge of attacks, loses effectiveness in flow analysis and abnormity detection. This paper proposes a new flow-based network behavior analysis model, which monitors and detects abnormity of network by building up a network behavior features base for each host. Based on this technology, a network monitor prototype system is designed and implemented. The system can detect malicious codes and track them in real time.
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Computer Engineering. 2008, 34(3): 168-170. https://doi.org/10.3969/j.issn.1000-3428.2008.03.059The important target of secure system is integrity and security. BLP is a classical security model, Clark-Wilson model can fully represent the needs of the integrity. A kind of multi-level security policy Model Based on Well-informed application (MBW) is presented. MBW uses well-informed application to flow information from low-level to high level and uses role-based ways to separate duty among users of operating well-informed application. Certification rules and enforcement rules make the role of operating system and application system clear in the process of implementing MBW.
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Computer Engineering. 2008, 34(3): 171-173. https://doi.org/10.3969/j.issn.1000-3428.2008.03.060In order to solve the problem of copyright protection for H.264 compressed video, a novel watermark algorithm of low bit-rate video is proposed. According to the distribution of DCT coefficients in H.264, by using the sign coding of the coefficients, watermark is embedded into the quantized DCT coefficients of the intra frame. For the sake of reducing the video distortion in watermarking, a quantized distortion compensation method is used. By using the mechanism of sign correlation detection, the original video is not needed in detection process which means the algorithm is blind. Experiment results show that the new algorithm can keep small distortion to video and well survive the H.264 compression attack.
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Computer Engineering. 2008, 34(3): 174-177. https://doi.org/10.3969/j.issn.1000-3428.2008.03.061Fragile digital watermark techniques provide effective solutions for multimedia content authentication and tamper-detection. This paper gives an overview of fragile digital watermark for image authentication, including the background, the basic characteristics and current algorithms. The performance of four fragile watermark algorithms in terms of their probabilities under signal processing operations is compared, such as cutting, scaling, JPEG compression and malicious alteration. The future orientations of research are prospected in the end.
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Computer Engineering. 2008, 34(3): 178-180,. https://doi.org/10.3969/j.issn.1000-3428.2008.03.062The trust search algorithm in the current trust models can not search and combine trust effectively and exactly. This paper uses subjective logic theory to quantify and compute trust, develops a new trust search algorithm based on subjective logic which is composed of an algorithm of obtaining trust paths and an algorithm of combination of trust paths. According to the experimental results, the algorithm makes the search of trust information effective, reduces the bad effect caused by redundant information, and makes the combination exact.
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Computer Engineering. 2008, 34(3): 181-182. https://doi.org/10.3969/j.issn.1000-3428.2008.03.063Intrusion detection is a process of identify the intrusion which had happened or not. Anomaly detection method is one of the main intrusion detection methods. Based on the traditional intrusion detection algorithm using single intrusion detection method, a hybrid method which combines HMM with STIDE is proposed. The HMM along with STIDE is used to categorize an unknown behavior to be either normal or an intrusion. Experimental results prove the hybrid method in low false positive rate with high detection rate.
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Computer Engineering. 2008, 34(3): 183-185. https://doi.org/10.3969/j.issn.1000-3428.2008.03.064Based on the research of traditional coverting channel, this paper presents a new way to implement coverting channel using the packet length, describes the way as a new mode of coverting channel (LAWB mode) with formal characterization, analyses the mode and experiments it respectively on IPv4 and IPv6 protocol.
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Computer Engineering. 2008, 34(3): 186-188,. https://doi.org/10.3969/j.issn.1000-3428.2008.03.065Model checking is a formal analysis technique with high automation. Wireless authentication protocol Linear MAKEP is modeled by finite automatas and authentication of the protocol is formally specified with CTL formula. The obtained model and formula are verified by a model checking tool SMV. The result shows that in Linear MAKEP, an intruder can impersonate the server to communicate with the client, thus, the protocol can not guarantee authentication. An improvement is given, making the protocol guarantee authentication.
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Computer Engineering. 2008, 34(3): 189-190. https://doi.org/10.3969/j.issn.1000-3428.2008.03.066This paper describes a family of cryptographic protocols in wireless and mobile networks, analyzes protocols with GNY logic. Seeing that EAP-TLS cryptographic is suffered from man-in-the-middle attack, solution is proposed, security deficiency and the security threats are found, and probable attacks are obtained.
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Computer Engineering. 2008, 34(3): 191-193. https://doi.org/10.3969/j.issn.1000-3428.2008.03.067This paper analyzes security threats and system flaws arising from the transfer of disease-causing mechanisms of biological immune system into present immune IDS schemes. An algorithm for optimizing measure parameters based on genetic algorithm and biological immunology is designed together with a hybrid intrusion detection engine. The scheme precludes the security problems by utilizing the useful metaphor of biological immune system and the prominent characteristics of genetic algorithm, such as automatic optimizing, parallel operating, and has stability, adaptability, robustness and parallel operating, and adaptability.
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Computer Engineering. 2008, 34(3): 194-195,. https://doi.org/10.3969/j.issn.1000-3428.2008.03.068This paper proposes a new intrusion detection method based on the Rough set and artificial immune, gains the rule detector by reducing the net data using rough set theory, designs the negative selection algorithm based on the Rough set using the rule detector and gets the immune detector through the algorithm, constructs the intrusion detection method based on Rough set and artificial immune using rule detector and immune detector. Experimental results indicate that the method hugely improves the efficiency of the intrusion detection system based on the artificial immune.
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Computer Engineering. 2008, 34(3): 196-198. https://doi.org/10.3969/j.issn.1000-3428.2008.03.069Usage control is one of the next generation technologies that protect the digital resources. Petri net can specify distributions, concurrencies and synchronizations of usage control and is the effective technology for describing and analyzing usage control model. This paper defines the rules of pre-usage authorization and ongoing-usage authorization in usage control model and expresses them with Petri nets. And a conclusion is drawn that the representations succeed in describing the policies of usage authorization. UCONA is expressed with colored Petri net.
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Computer Engineering. 2008, 34(3): 199-201,. https://doi.org/10.3969/j.issn.1000-3428.2008.03.070Utilizing Hess’s identity-based signature scheme, this paper proposes a public verifiability signcryption scheme. In the random oracle model, the proposed scheme is proved to be secure assuming the bilinear Diffle-Hellman problem is hard. As the authentication and recovery are separated in this scheme, anyone can identify the source of the ciphertext without the plaintext. What’s more, the proposed scheme has forward security. Even if the secret key is compromised, the attackers can not recover the signcryption of the past time. As compared with the most efficient Chen & Malone-Lee scheme to date, the proposed scheme decreases one pairing operation and only requires two pairing operations.
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Computer Engineering. 2008, 34(3): 202-204. https://doi.org/10.3969/j.issn.1000-3428.2008.03.071Adaboost algorithm is reliable and its precision is high. The article proposes a real-time pedestrian detection method based on the Adaboost algorithm. The expanded Haar-like characteristic is selected and calculated using integral map, the pedestrian detection cascaded classifiers with high accuracy are trained by Adaboost. Cascaded classifiers are loaded through VC to realize the real-time pedestrian detection. Experimental results indicate that the method is fast and reliable and meets the requirement of real-time system.
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Computer Engineering. 2008, 34(3): 205-206,. https://doi.org/10.3969/j.issn.1000-3428.2008.03.072Aiming at the characteristics of mobile search under the environment of Internet, this paper puts forward a mobile search model based on WAP. It makes use of existing search engines to get Web information, and makes full use of features of blocks of Web page to extract the theme block which is closely related to query request as the substitute for the primal page content, which is helpful to mobile users’ getting Web information on the move.
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Computer Engineering. 2008, 34(3): 207-209. https://doi.org/10.3969/j.issn.1000-3428.2008.03.073Based on hierarchy and information of International Patent Classification(IPC), this paper constructs character vectors on the different levels. Revision training is done combing with present patents based on the different levels. KNN algorithm is used to realize automated categorization of patent. Experimental results show that the method works well on the level of section, class and subclass, and the categorization performance is improved after revision training.
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Computer Engineering. 2008, 34(3): 210-212. https://doi.org/10.3969/j.issn.1000-3428.2008.03.074This paper presents a method for face detection in color images with complex backgrounds. Which adopts color balance method to correct the images color bias in the RGB color space based on "Gray World" hypothesis; detects skin color in the YES color space, introduced preprocessing techniques to reduce the searching areas of the face detection, and proposes a method that can detect arbitrary rotated faces based on the computation of the direction of the object. Template-matching method is used in the face candidate regions to locate face. The experiments show that the proposed face detection method provides better detection results to different illumination, different sizes and arbitrary rotated faces.
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Computer Engineering. 2008, 34(3): 213-214,. https://doi.org/10.3969/j.issn.1000-3428.2008.03.075It is the optimization effect of feature subset that always affects the accuracy of classification. Simple Genetic Algorithm(SGA) has the drawbacks of premature convergence and poor local searching ability. The crucial problem for improving SGA’s performance lies on how to solve the conflict between the population diversity and the individual selection pressure. This paper proposes an Improved Genetic Algorithm(IGA) in which adaptive constraint penalty is proposed while two operators, the Correlative Tournament Selection(CTS) and the Correlative Family Selection(CFS) are employed. Simulation results show that the performance of the new algorithm is much better than that of SGA when both are applied to feature selection in automatic modulation recognition.
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Computer Engineering. 2008, 34(3): 215-216,. https://doi.org/10.3969/j.issn.1000-3428.2008.03.076Based on red cell and white cell binary class space feature selection issue, this paper proposes one modified genetic algorithm for it. The modified genetic algorithm uses feature-fixing technology, and puts the Niche technology and adaptive mutation operator together to improve the genetic algorithm. The paper also introduces voting mechanism for it. Experimental results show that the algorithm performs better than Simple Genetic Algorithm(SGA), as it reduces the features and complexity of the Back Propogation Neural Network(BPNN) classifier apparently.
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Computer Engineering. 2008, 34(3): 217-219. https://doi.org/10.3969/j.issn.1000-3428.2008.03.077Traditional face recognition methods obtain universal subspaces by using all trained images. The subspace mainly represents the commonness of human faces with few sights of single person’s face. This paper presents a novel method named NMF-based image reconstruction for face recognition. It obtains the basis images by using each person’s pictures respectively and the features which are employed to reconstruct the images by mapping the test images to the basis images. The minimum reconstruction error is adopted to finish the facial recognition. The computer simulation in ORL face database illustrates that the method is effective.
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Computer Engineering. 2008, 34(3): 220-222. https://doi.org/10.3969/j.issn.1000-3428.2008.03.078Immune Genetic Algorithm(IGA) accelerates searching though introducing the immune operator, but it reduces the populations’ variety. This paper proposes an improved algorithm with group division and hybridization, which divides the initial populations into groups and hybridizing local best individuals between groups to improve searching speed and stability. Simulation results show that the performance of the algorithm improves about 10% and the near global optimal solution can be easy and quick.
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Computer Engineering. 2008, 34(3): 223-224,. https://doi.org/10.3969/j.issn.1000-3428.2008.03.079A second-order feature selection method based on complete 2DPCA is proposed for face recognition. The method based on complete 2DPCA uses immune algorithm and five-fold cross-validation method which is based on the nearest neighbor classifier to complete second-order selection of facial features in order to overcome the demerits of PCA and some improved PCA methods. Experiments based on ORL face library and Yale face library show that the method can achieve good recognition effect.
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Computer Engineering. 2008, 34(3): 225-227. https://doi.org/10.3969/j.issn.1000-3428.2008.03.080A study is made on feature extraction and a new feature extraction method is suggested. The method overcomes the shortcomings of the feature extraction method which was proposed by Roman W recently, which has no discriminant information. Face feature is obtained by the combination of PCA and LDA, the dimensionality is further reduced by using attribute reduction algorithm in the theory of rough set. Experimental results indicate that the proposed method has good performance.
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Computer Engineering. 2008, 34(3): 228-230,. https://doi.org/10.3969/j.issn.1000-3428.2008.03.081To resolve local optimization of the standard discrete Particle Swarm Optimization(PSO) algorithm, a Novel Particle Swarm Optimization(NPSO) algorithm with new motion equations is presented. Based on clonal selection theory and NPSO, Clonal Particle Swarm Optimization(CPSO) algorithm is proposed to design multiuser detector in Code Division Multiple Access(CDMA) systems. By using the clonal selection operator and the particle neutron, CPSO can carry out the stochastic search and experience learning. Simulation results for synchronous and asynchronous cases are provided to show that CPSO-based detector is superior to the conventional detector and some previous detectors in bit error rate, and has optimal performance like optimum multiuser detector.
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Computer Engineering. 2008, 34(3): 231-233. https://doi.org/10.3969/j.issn.1000-3428.2008.03.082Steel bars need to be packed according to a standard amount. It is difficult for the counting method of single camera object recognizing to handle problems like target-hiding. This paper proposes a new method of multi-camera data fusion to solve this problem, capturing target images from two cameras and recognizing them respectively, then fusing the recognizing results. This is to compensate and correct the single camera recognizing result and meet the goal of eliminating hiding problem. Experiments show that this method can solve target-hiding problem well, and can be applied to multi-target recognizing and tracking problem caused by occlusion and light limitation.
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Computer Engineering. 2008, 34(3): 234-236. https://doi.org/10.3969/j.issn.1000-3428.2008.03.083This paper puts forward an electronic commercial oriented automatic negotiation system based on the fuzzy similarity function. In each period of negotiation, agent concedes according to certain rules. On condition of assuring the required utility, agent tries search for an offer which is the most similar to the offer given by the opponent in the last period. The effectiveness of the method is tested by comparing it with Zeuthen strategy, which is the typical and theoretical result in principled negotiation. The enffluence of some parameters of the algorithm is given at the end of the paper.
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Computer Engineering. 2008, 34(3): 237-240. https://doi.org/10.3969/j.issn.1000-3428.2008.03.084This paper analyzes and researches the application of binocular vision system on mobile robot navigation, specially focusing on camera calibration, image segmentation, pattern recognition, and target distance detection. This paper gives a combined algorithm of recognition for different simple geometric objects which is in a particular 3D scene, Meanwhile the distance between the target and mobile robot, and the deviation angle of the target relative to robot can be directly detected by using binocular cameras structure.
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Computer Engineering. 2008, 34(3): 241-243. https://doi.org/10.3969/j.issn.1000-3428.2008.03.085This paper defines some local minutiae structures around core region, and according to the matching results of these structures, the fiducial point is extracted accurately. In addition, a novel attribute, the number of ridges between minutiae and the fiducial point, is introduced and it is invariant to transition, rotation and nonlinear distortion. Minutiae pairs that are not matched obviously can be recognized by comparing the attribute of them in the matching stage, and the final decision is made with the method of a changeable sized boundary box. Experimental results demonstrate the efficiency of the matching algorithm is increased by 10%~20%, and a high matching precision is also achieved.
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Computer Engineering. 2008, 34(3): 244-246. https://doi.org/10.3969/j.issn.1000-3428.2008.03.086A new method based on clustering algorithm is presented to detect anchorperson shot in news video. At first, representative frames of all shots are grouped by clustering based on face information. Then the color characteristics of persons and the border of persons are used to confirm anchorperson shot types. For consummating the anchorperson shot types, the method analyzes similarity of the background marginal of representative frames between anchorperson shot and others. Experimental results show that this method has high efficiency and adaptability.
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Computer Engineering. 2008, 34(3): 247-249,. https://doi.org/10.3969/j.issn.1000-3428.2008.03.087In peer-to-peer streaming system, because of the limitation of peer capacities and high bandwidth demand of multimedia applications, data scheduling policy to improve service of quality represents a major challenge. This paper presents a P2P-VoD system based on rateless codes, analyzes data scheduling policy based on minimum-delay of this system, gets a linear optimization model, and then discusses peers dynamics. Finally, the paper analyzes the property of the system and discusses future work.
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Research and Implementation of Key Technology of Real-time Subterranean Cave Scene Simulation SystemComputer Engineering. 2008, 34(3): 250-252. https://doi.org/10.3969/j.issn.1000-3428.2008.03.088In order to realize a subterranean cave scene simulation system, this paper investigates the key technology of scene simulation just like texture mapping, collision detection, model dynamic scheduling, object picking up. This paper presents the feasible application scheme, constructs three-dimensional model database of subterranean cave and the terrain above it. The virtual scene is also put forward and driven in Vega. The application layer design in VC++ using Vega API programming technology is completed and the application is published.
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Computer Engineering. 2008, 34(3): 253-255. https://doi.org/10.3969/j.issn.1000-3428.2008.03.089Stream media is the technique that transmits multimedia in the mode of data stream in data network. It is considered as one of mainstream applications in high speed network in the future. The research work of this paper is audio/video data collection and encode technique, which is the key technique of stream media, emphasizing resolving synchronization and transmission of twin-data stream. The research work has been applied synthetically in video information management platform and securities appraisement system of some securities co. ltd., which implements effectively the transmission and interactive of video data stream between multi-point on data network.
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Computer Engineering. 2008, 34(3): 256-257. https://doi.org/10.3969/j.issn.1000-3428.2008.03.090Quality standard is a basic problem in sampling inspection. To address this problem, this paper proposes an optimization method. Compared with conventional sampling inspection method, this method not only can provide reference standard for producer venture consumer, but also can avoid computing complex non-linearity equation. A special sampling inspection case is presented through computer simulation; the result shows that the optimization method of sampling inspection is feasible, and demonstrates that under the same condition of producer venture and consumer venture, the interval between acceptance quality level and non-acceptance quality level is less, and sampling inspection project’ quality is better.
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Computer Engineering. 2008, 34(3): 258-260. https://doi.org/10.3969/j.issn.1000-3428.2008.03.091This paper presents a field-bus based architecture of RFID integration with production line control system, and analyzes functions of the RFID acquisition processor in the architecture. Then a RFID acquisition processor with CAN(Control Area Network) interface is developed. After that, a production line control system which integrates RFID by CAN bus is built. Compared with traditional RFID applications in production line control, the system architecture is simpler, the information carried on tag is more abundant, and the data exchange is more direct and quicker. The experimental results show that the RFID integrated production line control system based on field-bus possesses high reliability and good real-time performance.
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Computer Engineering. 2008, 34(3): 261-262,. https://doi.org/10.3969/j.issn.1000-3428.2008.03.092This paper analyses main features of heavy mining machinery and design requirement of open controller, then designs and develops embedded control system based on ReWorks and PC104 hardware platform, and presents system functions, component structure, main modules and key technology. After research of open controller, network communication module and logical control module applicable for heavy mining machinery are refined.
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Computer Engineering. 2008, 34(3): 263-265. https://doi.org/10.3969/j.issn.1000-3428.2008.03.093This paper presents a resolution based on a digital wireless communication for video surveillance in elevator. It uses technologies including embedded software and hardware, wireless communication and digital video, which is suitable for mobile video surveillance in elevator. The system has a better performance of anti-jamming and small size of equipment, and the advantages of independence, no wiring. It can be installed flexibly, and be maintained easily. It can be conveniently implemented in the security defence inspecting and control, provide locomotive video services for the latter dynamic image processing and intelligent computing.
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Computer Engineering. 2008, 34(3): 266-268,. https://doi.org/10.3969/j.issn.1000-3428.2008.03.094This paper proposes a realizable plan for digital power system based on portable equipment on the base of an introduction to the main characters and developing status of digital power. It also presents the hardware and software design of smart battery, smart charger, POL converter and PMBus/SMBus host in detail. Experimental results show that the digital power system has such advantages as high performance target, favorable function of human-machine interaction, flexible control mode, etc. Hence, it possesses a strong practicability and extensive future applications.
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Computer Engineering. 2008, 34(3): 269-271. https://doi.org/10.3969/j.issn.1000-3428.2008.03.095A file access method from USB device to USB host is introduced. By using switch buffer built in memory of USB device, this method realizes the direct access to the file in USB host from USB device, which makes USB device access much larger external file than its storage capability. This method makes it possible that a portable player extends external harddisk with low cost and power saving.
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Computer Engineering. 2008, 34(3): 272-273,. https://doi.org/10.3969/j.issn.1000-3428.2008.03.096This paper presents an open controller architecture framework and its implementation based on real-time middleware criterion. The framework uses the distributed computing capability of middleware in order to realize interoperability and reusage of resource under system’s real-time demand. This paper also designs a mineral machine controller based on the open framework and CORBA and develops a trial-system.
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Computer Engineering. 2008, 34(3): 274-276. https://doi.org/10.3969/j.issn.1000-3428.2008.03.097Adequately considering the dynamic attribute and heterogeneous attribute of grid, the simulator platform of local grid task scheduling is constructed in OPNET with modeling design method. On the basis of this simulation platform, the performance of some grid task scheduling algorithms such as SF, LF, FCFS, EDF is tested. The simulation result shows that it provides a universal, modularizing and extensible simulation platform of grid task scheduling.
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Computer Engineering. 2008, 34(3): 277-279. https://doi.org/10.3969/j.issn.1000-3428.2008.03.098More and more attention is paid to form extraction in recent years, and a number of efficient results are obtained. Some of the presented algorithms can be used to process a form image with an arbitrary skew angle, but they are not the most efficient methods. A projection approach can detect form frame-lines more efficiently but fail to detect any line when the form slants severely. A new idea is given here to measure this sort of skew angle rapidly, it first detects one of the form’s frame lines by using the structural characteristics of digital lines, and then calculates the skew angle’s value. Along the directions determined by the angle, the form frame-lines are searched out. The method is both efficient and anti-skew.
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Computer Engineering. 2008, 34(3): 280-282. https://doi.org/10.3969/j.issn.1000-3428.2008.03.099Aiming at the design of the Ethernet/IP communication processor, this paper adopts S3C2410 ARM9 microprocessor and Windows CE.NET operating system to develop the communication processor’s Boot Loader program and I/O interface’s driver. The Boot Loader program, which is highly relevant to the hardware, initializes hardware platform and boots Windows CE.NET OS. While the I/O interface’s driver makes the OS detect peripherals automatically, and provides services for the applications to control the bottom equipments. Experimental results show that the Ethernet/IP communication processor operates steadily and credibly.
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Computer Engineering. 2008, 34(3): 283-封三. https://doi.org/10.3969/j.issn.1000-3428.2008.03.100This paper analyzes the characteristics of the classical Web-based applications and points out the shortages of applying window-based architecture to complicated system such as OA and ERP. A new page-container-based architecture is presented. The concepts of page container, relationship between page container and page and the communication between pages are discussed. The implementation framework and an instance of the system are given.
2024
Volume 50 No 3
Volume 50 No 3
(Started in 1975, Monthly)
Sponsored by：
East-China Institute of Computer Technology Shanghai Computer Society
Edited & Published by：
Editorial Board of Computer Engineering
Chief Editor：Jiang Bo
Executive Chief Editor:
Hu Bing
Tel：021-67092217
E-mail: ecice06@ecict.com.cn
CN: 31-1289/TP
ISSN: 1000-3428
Sponsored by：
East-China Institute of Computer Technology Shanghai Computer Society
Edited & Published by：
Editorial Board of Computer Engineering
Chief Editor：Jiang Bo
Executive Chief Editor:
Hu Bing
Tel：021-67092217
E-mail: ecice06@ecict.com.cn
CN: 31-1289/TP
ISSN: 1000-3428